At present, existing portable fire extinguishers are generally divided into stored-pressure dry powder fire extinguishers and portable aerosol fire extinguishers, wherein the stored-pressure dry powder fire extinguisher mainly have the following disadvantages: firstly, the stored-pressure dry powder fire extinguisher causes serious pollution to the environment and serious damage to articles; secondly, the stored-pressure dry powder fire extinguisher, which needs to store high pressure gases, is large in volume and heavy in weight; thirdly, the stored-pressure dry powder fire extinguisher, which is a high pressure container, has potential safety hazards and is more dangerous in a high temperature environment of a fire; fourthly, the stored-pressure dry powder fire extinguisher, which needs to go through regular inspection and verification, is high in routine maintenance costs etc. By contrast, the portable aerosol fire extinguisher has obvious advantages and mainly includes: a cartridge, a cartridge cover arranged on the cartridge, and a pyrotechnic composition, an ignition head, a coolant and a ceramic chip etc. arranged in the cartridge in turn and coated by a heat insulation material. Normally, after the pyrotechnic composition is ignited by the ignition head, a great deal of aerosol smog will be generated by the grain through rapid stratified combustion, and after being cooled by a coolant layer, these high temperature aerosols will be ejected from the cartridge cover of the cartridge to act on a fire source directly, thus extinguishing the fire. However, there are also some disadvantages. A coating defect, a pyrotechnic composition crack or a serious blockage of a gas channel may lead to a sudden rise of the pressure in the cartridge to deflagrate the grain. As a result, a high pressure gas will thrust the cartridge cover forwards and will be vented rapidly to throw the cartridge cover and other things in the cartridge forwards at an extremely high speed, thus causing a very large recoil force. The powerful recoil force drives the cartridge to move backwards rapidly, which is easy to cause an injury to an operator. At the same time, after explosion venting, the cartridge cover etc. of the fire extinguisher will also break away from the cartridge and fly outwards for a relatively long distance, which may cause other accidents. In addition, the cartridge of the fire extinguisher is easy to be loosened in an outer housing and is fixed by filling silicone in the cartridge body currently. However, the method generally needs to wait for silicone solidification by standing for seven to eight hours after silicone injection, thus a relatively large production site is required and the production efficiency is relatively low. Therefore, the problem of fixation of the cartridge of the fire extinguisher is a subject to be solved.